This invention relates to perfect bound books, and to apparatus and methods for manufacturing such books. Such perfect bound books typically comprise a book block having a plurality of paper text pages and a soft paper cover wrapped around one edge of the book block (referred to as spine). An adhesive is applied to the spine (or to a central portion of the cover) such that when the cover is wrapped around the book block the portion of the cover in engagement with the adhesive will be adhered to the spine. Of course, the adhesive also binds the edges of the text pages along the spine.
Typically, the cover of such perfect bound books is of a heavier stock than the text pages. The cover stock is also typically of a coated paper stock so as to give a better image when a color cover is printed, which is typical. In certain covers, only the outer face of the cover on which the cover graphics appears is so coated.
It has been known that if the outer face of the cover of such perfect bound books was covered or laminated with a clear plastic film, such covers were more durable and would protect the cover from water damage and hard use. However, because only the outer face of the cover was so laminated, these covers had a tendency to curl up away from the book block. It was known that if both the inner and outer faces of the cover were so laminated, such cover curling could be reduced or eliminated. However, if the inner face of the cover was so laminated, it was difficult for the adhesive to bind the cover to the spine of the book block.
In recent years, it has been advantageous to print such perfect bound books on demand. Apparatus for printing, binding and trimming such print on demand (POD) books is disclosed in my co-pending U.S. Patent Provisional Application No. 60/254,106, filed Dec. 8, 2000, and U.S. Provisional Patent Application No. 60/281,524 filed Apr. 4, 2001, now U.S. Patent Non-Provisional Application No. U.S. 2002/0064436 A1, published May 30, 2002, which is herewith incorporated by reference. As disclosed in this co-pending application, such POD books may be of different sizes and thicknesses with a limited range (e.g., any size between 5 inches×7 inches to 8½ inches×11 inches, and thicknesses from about 25 pages to 1000 or more pages). Reference may also be made to my U.S. Pat. No. 6,193,458 for apparatus and methods for binding and trimming perfect bound book. Reference may also be made to my U.S. Pat. No. 6,142,721 which discloses a system and method for perfect binding a cover to a book block in which a cold or room temperature adhesive is activated by an ultrasonic horn to bind the cover to the spine of the book block. Both of these afore-mentioned patents are herein incorporated by reference.
There has long been a need for a perfect bound book with a double laminated cover (i.e., a cover with both its inner and outer faces laminated) in which the adhesive will securely bind the inner face of the laminated cover to the spine of the book block.